In 1971 President Richard Nixon signed the National Cancer Act, formally launching a war on the second-leading cause of death in the United States. The legislation promised more funding and targeted government support for cancer research. "The time has come in America when the same kind of concentrated effort that split the atom and took man to the moon should be turned toward conquering this dread disease," Nixon urged in his State of the Union Address earlier that year.

You might expect Devra Davis, director of the Center for Environmental Oncology at the University of Pittsburgh Cancer Institute, to see this as a watershed moment in cancer research, especially since both of her parents died of the disease. Instead Davis callsAmerica's war on cancer shortsighted and misguided. In this provocative and often personal book, she argues that we've been fighting the wrong enemy by trying to cure the disease instead of paying enough attention to its causes.

Davis recounts debates over major carcinogens including cigarettes (her most detailed case), asbestos and vinyl chloride to show how industries that produce or rely on these goods have obscured evidence that they were dangerous. Their methods will be familiar to journalists who cover global climate change: obscuring what scientific findings really showed, funding research that pointed the finger elsewhere, and creating extreme standards for proof of harm — for example, by questioning whether results from animal studies were applicable to humans. In many instances companies knew that their products were harmful based on illness rates in their own workforces, but used legal shields to protect this data as proprietary information.

As Davis stresses, some U.S. and European researchers had shown clear statistical links between cancer and exposure to harmful substances as early as the 1930s. Citing these connections, leaders in Hitler's Germany exhorted against cigarette smoking, food preservatives, industrial toxins and artificial colorings as threats to national health. But after World War II, Davis contends, "enthusiasm for modern industrial advances" overwhelmed knowledge about cancer hazards.

Studies on smoking and health in the 1950s and 1960s, which laid the ground for the Surgeon General's 1964 statement that smoking was "a major cause of lung cancer," also spotlighted epidemiology as a key public health tool. Davis's book is a good introduction to the exacting process of comparing sick and healthy groups of people and sorting through information to "make sense of [the] messy, large-scale data of real lives." For example, she notes, big differences between groups are less likely to be random than small ones, and studying a large number of cases increases the odds of finding differences. Davis relates these methodological discussions back to issues like smoking and shows how industries have stalled some regulatory actions for decades by insisting on elusive forms of proof.

This book is frustrating to read, both because of what it says and because it could have used a more disciplined editor. It's long, the chronology jumps around within chapters, and some sections (such as a 25-page overview of Nazi science, leading up to what German researchers knew about tobacco hazards) don't advance the central story. Davis can get melodramatic: for example, she confides, "I have learned from others, whom I can't name at this point, that the files of many large multinational businesses could easily tell us about many more health risks associated with workplace exposures of the past."

In conclusion, however, Davis asks a critical question: if, as she believes, our system for identifying and addressing preventable causes of environmental cancer doesn't work, what should we do? Today the Toxic Substances Control Act requires anyone who knows that an activity threatens public health or safety to report it, but Davis says that this just discourages companies from keeping the kind of workplace health data that might give researchers more information about dangerous exposures. She has some hope for the European Union's REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) program, which requires companies that produce chemicals to document that these products are safe, but says it's too soon to tell if the program will work as intended.

Davis suggests some kind of process modeled after South Africa's postapartheid Truth and Reconciliation Commission to create a neutral forum where industries, scientists and regulators could exchange information on environmental health risks, funded by industries that produce risky materials. But without a whole new approach to testing and regulating potentially toxic substances, it's hard to see what incentive chemical or pharmaceutical manufacturers would have for making internal data public. It would be fascinating to see Davis collaborate with a publicpolicy expert on a book about legal and regulatory options to help modern societies protect citizens from the fruits of progress.